Hoist sling with tubular frame



March 24. 1970 G. v. MOORE 3,502,364

HOIST SLING WITH TUBULAR FRAME Filed July 12, 1968 y; 72 INVENTOR.

i GeogyeVZ/Zooze 7 If 5 I I A 7'TORNEY United States Patent 3,502,364 HOlST SLING WITH TUBULAR FRAME George V. Moore, Milford, Mich, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed July 12, 1968, Ser. No. 744,393 Int. Cl. B66c 1/00 US. Cl. 294-67 6 Claims ABSTRACT OF THE DISCLOSURE A sling of tubular construction for use with a hoist is disclosed wherein the hoist has a load ring with three chain members depending therefrom and the sling is a spreader for the chain members having three attaching points for preventing movement of the chain relative to the sling. The sling is adjustable on the chains, when unloaded, to permit the center of gravity, of the load to be raised, to be aligned with the load ring of the hoist.

The present invention is related to hoist slings and more particularly to slings of tubular construction which are adjustable on the hoist to align the hoisting force with the center of gravity of the load.

Many of the hoist slings presently in use are constructed of heavy steel structure such as I beam or the like. Also, the majority of these slings have a single chain member secured between the hoist load ring and the sling and a plurality of chain members secured to the sling depending downwardly therefrom to be attached to a load. To place the center of gravity of the load under the load ring, during hoisting, it is necessary to locate the lifting points on the load equally about the center of gravity or move the point on the sling where the load ring chain member is secured so that it is aligned with the center of gravity. It is not generally feasible or possible to locate the lifting points satisfactorily. To relocate the load ring chain on the sling generally requires a second hoist to hold the sling above the load while the load ring chain is moved. Also, the structure of the sling must have sufiicient strength to carry the weight of the load. The present invention overcomes these disadvantages.

The present sling is of lightweight tubular construction which permits it to be readily movable by a man. The chains used with this sling are continuous between the load ring to the load and, therefore, carry the weight of the load to be raised while the major forces impressed on the sling structure are compressive. Also, to move the sling relative to the chain members, so that the center of gravity of the load is favorably located, it is only necessary to release the tension on the chain by lowering the hoist slightly thus permitting the sling to be freely moved up or down the chain members.

It is, therefore, an object of this invention to provide an improved sling which is of lightweight construction and easily movable along the hoisting chains.

It is another object of this invention to provide an improved hoist sling which is easily adjustable to locate the center of gravity of the load properly under the hoist.

These and other objects and advantages and modifications will become apparent from the following description and drawings which are illustrative of the invention defined in the appended claims.

FIGURE 1 is an isometric view of the invention with a hoist.

FIGURE 2 is a plan view of a sling constructed according to the present invention.

FIGURE 3 is a plan view of another sling constructed according to the present invention.

FIGURE 4 is an enlarged top view of the chain attachment clevis on the sling.

3,502,364 Patented Mar. 24, 1970 ice FIGURE 5 is an enlarged side view of the chain attachment clevis on the sling.

FIGURE 6 is a partial view showing a modification.

FIGURE 7 is a sectional view taken along line 7-7 in FIGURE 6'.

FIGURE '8 is a sectional view taken along line 8-8 in FIGURE 6.

Referring to the drawings, there is shown in FIGURE 1 a hoisting system including a hoist structure 10, a lift chain 12 and a load ring 14 secured to the lift chain 12. Secured to the load ring 14 are load chains 16, 18 and 20 which are adapted to be connected to the load to be lifted at points 20, 24 and 26. A sling member 28, generally triangular in shape, is used as a spreader bar to maintain the load chain in a desired position and to locate the lift ring 14 directly above the center of gravity of the load 31 to be lifted. The sling 28, as seen in FIGURE 2, has three tubular leg members 32, 34 and 36 which are welded or otherwise secured together to form a triangle with clevis 38, 40 and 42 secured at each of the angles of the triangle. Tubular support members 44, 46 and 48 are secured by welding or clamping between the tubular members 32, 34 and 36 to increase the structural rigidity of the sling 28. Due to the fact that the load chains are continuous between the load and the load ring, the forces imposed upon the sling 28 are mainly compressive thus permitting the sling 28 to be of lightweight tubular construction.

As seen in FIGURES 4 and 5, the clevis has two finger members 50 and 52 with a space between them being sufficient to permit the depth of a chain ring, such as 54, to pass between them, but is sufficiently narrow to prevent the chain width, such as 56, from passing between them. Thus, the sling remains stationary relative to the load chain during lifting, but is easily adjustable on the chain when it is not under tension. To align the center of gravity 30, with load ring 14, the clevis i.e. 38, and, therefore, the legs, i.e. 32 and 34, of the sling may be moved upwardly or downwardly on the load chain, i.e. 16. Thus, the position at the load ring 14, relative to the center of gravity 30, is readily adjustable.

The sling 28', shown in FIGURE 3, is a modification in which the sling has a cylindrical central hub member 58 with three legs 60, extending outwardly therefrom. The legs 60 are formed of two separate members 62 and 64. One of the members 62 is tubular and secured to the hub 58 and the other members 64 are cylindrical and telescopically mounted within the member 62. A clevis 38, similar to clevis 38, is secured to the outer end of cylindrical member 64. A pin 70 extends through both members 62 and 64 which pin then may be removed to permit telescoping of members 64 into and out of member 62. The member 64 has a plurality of bores 66 into which the pin 70 is placed when the desired length of the leg 60 has been established. By changing the length of the leg 60, it is possible to align the center of gravity of the load with the load ring. Also, adjustment of the length of legs 60 permits the use of the sling 28' with various sizes and shapes 'of loads.

The sling member 28 may also be made adjustable, as shown by the sling 28" in FIGURE 6. The sling 28" has three legs arranged to form a triangle. The leg 34' is formed of telescoping members 72 and 74 while the leg 32 has telescoping members 76 and 72. A separate clevis 38" joins the telescoping members 72 and 76 to form an angle A. The telescoping member 72 is adjustable linearly within the telescoping member 74 and the telescoping member 76 is likewise adjustable within a similar telescoping member. A pin 80, which extends through the telescoping members 72 and 74, is removable to permit one of a plurality of bores 82 in member 72, to be aligned with openings 84 in member 74. As the length of a leg Thus, it is readily apparent that by either adjusting the size or shape of the sling or by relocating the sling on the load chain, the center of gravity of the load to be lifted can be aligned with the hoist load ring.

Many modifications may be made of the above described illustrative embodiments of the invention defined in the appended claims.

What is claimed is:

1. A hoist mechanism including lifting means for raising and lowering a load having a lift chain, a load ring attached to said lift chain, and three load chains each having one end attached to said load ring and another end adapted to be connected with the load to be raised or lowered; and sling means having three legs, and three chain connecting means each connected to at least one of said legs and detachably connected to said load chains, said sling means engaging and maintaining a spaced relation between said load chains and being adjustable on said load chains to align the center of gravity of the load with the load ring.

2. The invention defined in claim 1 and said sling being in the shape of a triangle and said chain connected means each being connected to adjacent legs at the angle formed thereby.

3. The invention defined in claim 2 and each of said legs having telescopic construction to permit adjustment of the length of said legs and means connecting said adjacent legs and said chain connecting means for permitting angular adjustment between said legs when their length is adjusted.

4. The invention defined in claim 1 and said sling means including hub means with each of said legs extending radially outwardly from said hub means.

5. The invention defined in claim 4 and each of said legs being of telescopic construction to permit adjustment of their length.

6. A sling adapted to be used with a hoist having a load ring and three load chains depending from the load ring; said sling comprising three compression load carrying legs, and clevis means attached to each of said legs and being adapted to engage said load chains, said legs being individually adjustable lengthwise and said clevis means being positionable on said load chain to align 'the center of gravity of the load with the load ring.

References Cited UNITED STATES PATENTS 1,397,593 11/ 1921 Magee 29481 FOREIGN PATENTS 523,364 4/1956 Canada.

ANDRES H. NIELSEN, Primary Examiner mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 502 364 Dated h h 24 192 Inventor(s) George V, M;

It is certified that error appears in the aboveand that said Letters Patent are hereby corrected as identified patent shown below:

Column 2, line 13, after "points," delete "20" and insert 22 SIGNED AND SEALED AUG 4 -1970 Atbest:

Ed an! 2 m1 3. 5m, mcomissionar or Pamta Auesting Officer 

